The Research Behind Passive Management

In the 1960s, University of Chicago professor of economics, Eugene Fama, conducted extensive research on stock price patterns, which led to his development of the Efficient Market Hypothesis (EMH). The EMH maintains that market prices fully reflect all available information and expectations, so current stock prices are the best approximation of a company’s intrinsic value. Attempts to systematically identify and exploit stocks that are mispriced on the basis of information typically fail because stock price movements are largely random and are primarily driven by unforeseen events. Although mispricing can occur, there is no predictable pattern for their occurrence that results in consistent outperformance. The efficient markets hypothesis implies that no active investor will consistently beat the market over long periods of time, except by chance, which means active management strategies using stock selection and market timing cannot consistently add value enough to outperform passive management strategies.

Sharpe concluded that, as a whole, active fund managers underperform passive fund managers, not because there is anything inherently wrong in their financial strategies, but simply because of the laws of arithmetic. For active managers to outperform the market, they have to achieve a return that can overcome their fund expenses, which are much higher than passive funds due to higher management fees, higher trading costs and higher turnover. This is consistent with Sharpe’s research which shows that, as a group, active managers underperform the market by an amount equivalent to their average fees and expenses.

When a passive management strategy is employed, there is no need to expend time or resources on stock selection or market timing. Because of the short-term randomness of returns, investors would be better served through a passive, structured portfolio based on asset classdiversification to manage uncertainty and position the portfolios for long-term growth in the capital markets.